1. Field of the Invention
The present invention relates generally to the use of safety hypodermic syringes and, more particularly, but not by way of limitation, to a method of use of a prefilled, single dose, one time use, self-destructing, auto disabling hypodermic syringe with an injection molded barrel.
2. Description of the Related Art (Including Information Disclosed Under 37 C.F.R. 1.97 and 1.98)
The alarming increase of human-fluid borne infectious diseases, their various avenues of spread, and especially, the increase risk of spread due to multiple uses or accidental needle sticks of hypodermic injection systems cannot be ignored.
Over the last twenty years, there have been numerous developments in the field of single dose, prefilled, disposable syringes. U.S. Pat. No. 4,596,561 to Meyer et al., describes and claims a non-reusable syringe comprising a tamper-proof packaging which insures that the proper medication is contained in the barrel, free of any contaminant.
U.S. Pat. No. 5,575,776 to Bleiweiss, discloses and claims a single dose, prefilled, disposable syringe arrangement. The '776 patent's system comprises an outer casing surrounding the syringe in the packaged state, which is collapsible to act as a plunger during use of the syringe. Bleiweiss' patent stresses the single use capability of the syringe, followed by secured disposal and non-reuse.
Pre-filled syringes were originally made from glass or borosilicate. As it is well known in the art, glass structures allow variations in the pH of the contents thus resulting in at least some degradation. Another disadvantage of borosilicate syringes is the need for a medical grade silicone stopper lubricant to advance the plunger. In many cases, silicone tends to break down the contents' proteins thus decreasing the effectiveness of the drug being administered. In addition, injuries from glass syringes and needle-sticks have allowed the spread of blood borne pathogen diseases such as acute or chronic hepatitis, HIV, or AIDS.
In more recent times, some of the problems outlined above have escalated. Caregivers in the hospital, hospice and home-healthcare environments are further exposed to human fluid borne, potentially infectious, diseases while conducting procedures in patients who, due to their condition, may not hold still during an injection. Another potentially dangerous situation takes place if the caregiver drops the syringe accidentally receiving a needle stick or is stuck while cleaning a tray. There have been reported cases where a custodian has received a potentially infectious injury while cleaning the pieces of broken glass from a syringe. Caregiver and worker injuries can significantly increase the costs of medical care as well as insurance for the healthcare facility. All of those costs are usually passed on to the patients.
Healthcare providers are supposed to deposit used syringes in a sharps container immediately after use. Many caregivers place syringes on a tray or cart and injuries can and do occur for failure to follow the proper disposal protocol. Medical device companies have tried to manufacture add on needle stick avoidance devices and spring-loaded covers or shields for the glass syringe. Many of the commercially available devices have unacceptably high failure rates and, in some instances, cannot be securely engaged to the syringe. Most efforts in the stick-avoidance area have taken place in the context of manufacturers trying to assist healthcare providers in compliance with the newly enacted FED/OSHA mandate 29 CFR Part 1910 and European Parliament resolutions; Occupational Exposure to Blood borne Pathogens; Needle sticks and other Sharps Injuries.
Because of the many shortcomings of glass syringes, the next generation of prefilled syringes of the prior art was manufactured using polypropylene. Some polypropylene prefilled syringes of the prior art even had spring-loaded retractable needles, hinged needle guards and flip-over covers. The type of highly clarified polypropylene resin used presented problems in that it posed a risk of leechables and extractables in the resin altering the contents of the medication. In addition, the stopper required a medical grade silicone lubricant to advance the plunger. It is well known in the art that silicone can break down the proteins in the medication, rendering it less effective to the patient. The FDA has denied new drug application approvals of medications being administered via prefilled syringes based on laboratory testing and two-year shelf life restrictions. Accordingly, the safety syringes in the market today are primarily used as general or multi purpose syringes.
Most recently, cyclic olefin copolymer (“COC”) has been introduced as the new FDA approved state-of-the-art replacement for glass. COC has excellent barrier properties and is virtually shatterproof. COC also has the look of glass and does not contain crystalline, which makes it as clear as glass. COC is also bio-compatible, so that it does not alter pre-filled medications in the ways polypropylene syringes can. Those characteristics make COC an ideal material to aid overcoming some of the shortcomings of the safety syringe prior art mentioned above.
In the case of COC syringes, many medical manufacturers “blow-mold” the resin into the shape of a syringe component. COC syringes, which lack most, if not all, of the required safety features, present most of the same shortcomings evidenced in the existing art, including needle-sticks and accidental, unintentional or intentional re-use. Furthermore, the COC syringe's stopper still requires a medical grade silicone lubricant to advance the plunger. Again, the silicone can break down proteins in the syringe's content, potentially diminishing the effectiveness of the medication being administered.
COC medical ampoules or blow molded vials are FDA approved and have gained a large percentage of market share. They cannot be blow molded and manufactured as a cartridge because both ends are initially open. During the manufacturing process, the back end is sealed with a piston plunger and the front end is sealed with thermoplastic elastomer (“TPE”), or a rubber seal and an aluminum cap.
Despite prior attempts to comply with FED/OSHA and European Parliament mandates, no compliant, mechanically suitable engineered safety syringe exists for use by the professional caregiver or patient for the safest possible biocompatible safety syringe with anti-needle-stick and auto-disable features. The present invention fulfills all of those requirements and provides an alternative arrangement which effectively addresses and cures all of the shortcomings of the prior art. The present invention is the first pre-filled integrated engineered safety syringe.
In addition, none of the prior art discloses a syringe for doses under 3.0 mL. A small bio-compatible safety syringe is critically needed to address two problems. The first problem is the shortage of refrigerated or temperature-controlled space in most medical settings. A small syringe with a short plunger can help to resolve space issues for low volume vaccines, biologics and allergens. Pediatrics is the second area where a small syringe is needed. A small syringe can accommodate a smaller needle hub and needle. The present invention can be scaled down in length for doses as small as 0.5 mL. A small-sized hub for the smaller syringe is also disclosed.
Applicant's pre-filled syringe invention addresses and solves the problems of the prior art syringes by combining the use of COC injection molding with the advantages presented by the ampoule cartridge and the traditional safety syringe all integrated into a single compliant device. Molding the pre-filled ampoule cartridge with minimal draft enables the plunger to be partially self-lubricated by the syringe's contents and minimizes the use of silicone. The addition of an internal auto disabling coupler to the piston plunger allows the device to be used only a single time. In addition, the applicant's syringe invention comprises opposing tabs at the proximal end, a universal hub attached to the distal end, and an integrated safety sleeve with forward mounted opposing tabs.